What is the difference between “if” statements with “then” at the end?

Question

What\'s the difference between these two Ruby if statements when we put a then at the end of the if statement?

if(val          


        

Answer 1

Here's a quick tip that is not directly related to your question: in Ruby, there is no such thing as an if statement. In fact, in Ruby, there are no statements at all. Everything is an expression. An if expression returns the value of the last expression that was evaluated in the branch that was taken.

So, there is no need to write

if condition
  foo(something)
else
  foo(something_else)
end

This would better be written as

foo(
  if condition
    something
  else
    something_else
  end
)

Or as a one-liner

foo(if condition then something else something_else end)

In your example:

something.meth(if val == 'hi' then 'hello' else 'right' end)

Note: Ruby also has a ternary operator (condition ? then_branch : else_branch) but that is completely unnecessary and should be avoided. The only reason why the ternary operator is needed in languages like C is because in C if is a statement and thus cannot return a value. You need the ternary operator, because it is an expression and is the only way to return a value from a conditional. But in Ruby, if is already an expression, so there is really no need for a ternary operator.